Aircraft of the type of interest in the present document comprise at least one intermediate deck that extends across an aircraft fuselage in order to create a multi-level design. In a commercial aircraft such an intermediate deck is, for example, provided in order to install passenger seats thereon, which passenger seats occupy the upper region of the aircraft fuselage. In contrast to this, the lower region of the aircraft fuselage, i.e. the region below the intermediate deck, is normally used as a cargo hold. In particular in case of large-volume aircraft fuselages, the corresponding large-area intermediate decks need to be additionally supported relative to the aircraft fuselage in order to provide adequate static stability. For this purpose the supporting struts of interest in this document, which are detachably attached between the at least one intermediate deck and the aircraft fuselage, are used.
From the general state of the art it is known to produce supporting struts by wrapping carbon fibre threads around a mandrel, which carbon fibre threads are then embedded in epoxy resin. Such winding usually takes place at an angle of approximately 45° relative to the longitudinal axis of the mandrel, and subsequently, in order to improve stability, at an angle of approximately 70° relative to the longitudinal axis of the mandrel. After the material has been wound onto the mandrel and after the epoxy resin has cured or hardened, the mandrel can be removed, and a hollow-cylindrical rod body results, which on both ends is fitted out with rod ends in order to make possible attachment to the intermediate deck and the aircraft fuselage respectively.
Such rod bodies are associated with a disadvantage as a result of the deviation of the fibre alignment from the optimal alignment, which deviation is due to the production process, thus resulting in thicker wall thicknesses in the dimensioning that is required to achieve adequate buckling resistance. Associated with this, the rod body has a comparatively heavier weight, which is basically undesirable in aircraft construction. Rod bodies produced in this way are associated with a further disadvantage in that shock loading can have a significant negative effect on the stability of the supporting strut. Known supporting struts are thus comparatively susceptible to damage. Furthermore, due to the material used, meeting the required fire-resistance characteristics is problematic or often achievable only with the use of additional measures, for example special coatings.